LP2981A-33DBVT Equivalent & Substitute Parts

Part Overview

The LP2981A-33DBVT is a linear voltage regulator IC from Texas Instruments, delivering a fixed 3.3V output at 100mA in a SOT-23-5 surface mount package. This device is classified as Last Time Buy, indicating discontinued production. The part provides positive fixed output configuration with integrated enable control and comprehensive protection features including over-current, over-temperature, and short-circuit protection. Finding equivalent and substitute parts is necessary due to the Last Time Buy status and to ensure design flexibility for procurement and long-term supply chain continuity.

Key Parameters

Parameter	Value
Output Voltage (Fixed)	3.3V
Output Current	100mA
Input Voltage (Max)	16V
Dropout Voltage (Max)	0.37V @ 100mA
Quiescent Current	95 µA
PSRR	63dB (1kHz)
Package	SOT-23-5 (SC-74A)
Control Features	Enable
Protection Features	Over Current, Over Temperature, Short Circuit
Operating Temperature	-40°C ~ 125°C
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitute parts for the LP2981A-33DBVT are classified based on strict parameter matching across the following critical criteria:

Primary Substitution Criteria:

Output voltage: 3.3V fixed
Output current capability: 100mA
Input voltage rating: 16V maximum
Dropout voltage: 0.37V @ 100mA
Package type: SOT-23-5 (SC-74A)
Control features: Enable function
Protection: Over-current, over-temperature, short-circuit
Operating temperature range: -40°C ~ 125°C
Compliance: ROHS3, REACH Unaffected

MFR Recommended Substitutes (Texas Instruments LP2981 Series): Parts LP2981AIM5X-3.3/NOPB and LP2981IM5-3.3/NOPB are manufacturer-recommended alternatives with Active product status, identical electrical specifications, and full parameter compatibility.

Parametric Equivalents (Texas Instruments LP2981 Series): Parts LP2981-33DBVR, LP2981-33DBVT, LP2981A-33DBVR, LP2981A-33DBVTG4, LP2981AIM5-3.3/NOPB, and LP2981IM5X-3.3/NOPB meet all electrical and mechanical requirements with identical output characteristics and protection features.

Cross-Manufacturer Alternatives (STMicroelectronics LD2980 Series): Parts LD2980ABM33TR and LD2980CM33TR provide functional equivalence with the same 3.3V output and SOT-23-5 package. However, these parts have reduced output current (50mA versus 100mA) and are suitable only for applications requiring ≤50mA output current.

Parameter Comparison

Part Number	Manufacturer	Output Current	Dropout Voltage	Quiescent Current	Product Status	Packaging
LP2981A-33DBVT	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Last Time Buy	Cut Tape (CT)
LP2981AIM5X-3.3/NOPB	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	Cut Tape (CT) & Digi-Reel®
LP2981IM5-3.3/NOPB	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	Cut Tape (CT) & Digi-Reel®
LP2981-33DBVR	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	Cut Tape (CT) & Digi-Reel®
LP2981-33DBVT	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Last Time Buy	Cut Tape (CT) & Digi-Reel®
LP2981A-33DBVR	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	Cut Tape (CT) & Digi-Reel®
LP2981A-33DBVTG4	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Discontinued at DiGi Electronics	Tape & Reel (TR)
LP2981AIM5-3.3/NOPB	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	Cut Tape (CT) & Digi-Reel®
LP2981IM5X-3.3/NOPB	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	Cut Tape (CT) & Digi-Reel®
LD2980ABM33TR	STMicroelectronics	50mA	0.225V @ 50mA	150 µA	Active	Cut Tape (CT) & Digi-Reel®
LD2980CM33TR	STMicroelectronics	50mA	0.225V @ 50mA	150 µA	Active	Cut Tape (CT) & Digi-Reel®

Engineering Selection Recommendations

Primary Selection (Full Compatibility): For direct replacement with identical electrical performance and 100mA output capability, select from the Active status Texas Instruments LP2981 series variants: LP2981AIM5X-3.3/NOPB, LP2981IM5-3.3/NOPB, LP2981-33DBVR, LP2981A-33DBVR, LP2981AIM5-3.3/NOPB, or LP2981IM5X-3.3/NOPB. These parts maintain full parameter equivalence and offer superior supply chain availability compared to the Last Time Buy main part.

Secondary Selection (Reduced Current Applications): For applications requiring ≤50mA output current, STMicroelectronics LD2980ABM33TR or LD2980CM33TR provide functional equivalence with identical 3.3V output, SOT-23-5 package, and Active product status. These parts feature improved dropout voltage (0.225V @ 50mA) but reduced quiescent current capability (150 µA).

Compliance Considerations: All listed substitute parts maintain ROHS3 compliance and REACH Unaffected status, ensuring regulatory alignment with the original LP2981A-33DBVT specification.

Frequently Asked Questions (FAQ)

Q: Can LP2981IM5-3.3/NOPB directly replace LP2981A-33DBVT in existing designs? A: Yes. Both parts deliver 100mA at 3.3V with 0.37V dropout voltage, identical quiescent current (95 µA), and SOT-23-5 packaging. The primary difference is product status: LP2981IM5-3.3/NOPB is Active, while LP2981A-33DBVT is Last Time Buy.

Q: What is the difference between Cut Tape (CT) and Tape & Reel (TR) packaging? A: Cut Tape packaging is supplied as individual strips suitable for manual assembly or small-volume production. Tape & Reel packaging is supplied on continuous reels for automated pick-and-place assembly. Both contain identical die and electrical performance.

Q: Why do LD2980 parts have lower output current than LP2981 parts? A: The LD2980 series is designed for lower current applications (50mA maximum) compared to the LP2981 series (100mA). Selection depends on circuit current requirements. LD2980 parts are not suitable for designs requiring >50mA output.

Q: Are all substitute parts RoHS3 compliant? A: Yes. All listed substitute parts maintain ROHS3 compliance and REACH Unaffected status, matching the original LP2981A-33DBVT specification.

Q: Which substitute offers the best long-term availability? A: LP2981AIM5X-3.3/NOPB and LP2981IM5-3.3/NOPB carry Active product status with highest inventory levels (7272 and 18400 units respectively), providing superior supply chain continuity compared to Last Time Buy or Discontinued alternatives.

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